What is string.to_owned()

Phined answer:

to_owned is a method provided by the ToOwned trait in Rust, which is a generalization of the Clone trait for borrowed data. While both clone() and to_owned() can be used to create a copy of a value, they differ in their behavior for certain types, such as string slices (&str) and array slices (&[T]) Source 2.

When using clone() on borrowed types like &str or &[T], it returns a copy with the same borrowed type (&str or &[T]). However, when using to_owned() on these borrowed types, it returns an owned version of the type, such as a String for &str or a Vec<T> for &[T] Source 2.

For example:

#![allow(unused)]
fn main() {
let str = "a"; // type &str 
let cloned_str = str.clone(); // type &str
}

#![allow(unused)]
fn main() {
let str = "a"; // type &str 
let owned_str = str.to_owned(); // type String
}

In general, you can use clone() when you want a copy of the same type, and to_owned() when you want to create an owned copy from borrowed data. The ToOwned trait ensures that the duplicate value has ownership, even if it requires using a different data type, such as a String or a Vec<T> for a &str or &[T] Source 2.

As mentioned in Source 4, some developers prefer using clone() when they want an object of the same type and to_owned() when the types are different. However, this distinction is mostly stylistic, and both methods can be used interchangeably in many cases.